Patent Literature 1 discloses an exhaust emission control device for an internal combustion engine that burns and removes particulate matter (PM) contained in exhaust gas in an exhaust gas purifying catalyst. Air that is contained in exhaust gas exhibits the function of carrying heat in the catalyst away in the process of passing through the exhaust gas purifying catalyst and restraining increase in the catalyst temperature. Consequently, there is the fear that at the time of deceleration of the engine, the amount of exhaust gas decreases, and the temperature of the exhaust gas purifying catalyst excessively increases. In the device of Patent Literature 1, as the countermeasure to the above, control of restraining increase in the intake air amount is performed when the engine decelerates in the state where the accumulation amount of PM is large.
Following is a list of patent literatures which the applicant has noticed as related arts of embodiments the present invention.
Patent Literature 1: JP 2005-155500 A
Patent Literature 2: JP 2003-83067 A